1. Field of the Invention
The present invention generally relates to a single-reel recording tape cartridge and, more particularly, to the single-reel recording tape cartridge of a kind including a leader piece which is, when in use, captured by a catch member, forming a part of an automatic tape threading mechanism built in the tape drive, so that a length of magnetic recording tape can be drawn out of the cartridge.
2. Description of the Prior Art
The tape cartridge of the kind referred to above is well known in the art and is disclosed in, for example, the Japanese Laid-open patent publications No. 11-7749, published Jan. 12, 1999, and No. 11-232826, published Aug. 27, 1999, and U.S. Pat. No. 5,883,771 issued Mar. 16, 1999. In general, the single-reel recording tape cartridge includes a generally rectangular cartridge housing having a reel chamber defined therein, and a single reel freely rotatably accommodated within the reel chamber and having a roll of a length of magnetic recording tape mounted thereon. The length of magnetic recording tape has one end anchored to a reel hub and the opposite end coupled with the leader piece. When the cartridge is in use having been loaded into a tape drive for data recording or retrieval, a catch member forming a part of an automatic reeling mechanism built in the tape drive captures the leader piece to draw the magnetic recording tape out of the cartridge housing in readiness for data recording or retrieval in cooperation with a magnetic read/write head.
The leader piece disclosed in the publication No. 11-7749 is a generally hook-shaped, plastics-molded leader that is, when the cartridge is not in use, retained at a retracted position in a cantilevered fashion by means of a pair of projections disposed inside the cartridge housing at a location inwardly of a tape window in the cartridge housing.
The leader piece disclosed in the publication No. 11-232826 is in the form of a metal pin having its opposite ends formed with an engagement boss. The leader piece disclosed in this publication is, when the cartridge is not in use, retained at a retracted position with its opposite engagement bosses received within generally U-shaped bearing recesses defined in top and bottom panels of the cartridge. Barrier walls for preventing a spring element from being displaced in position are formed adjacent the associated bearing recesses so as to protrude parallel to the top and bottom panels, respectively. The spring element is in the form of a torsion spring having opposite spring arms, one of which is formed with a generally arcuate portion adapted to engage the corresponding engagement boss when the leader piece is not in use.
As discussed above, the single-reel recording tape cartridge in general makes use of the leader piece to ensure a sure withdrawal of the length of magnetic recording tape out of the cartridge housing in cooperation with the catch member. In order for the catch member to capture the leader piece properly when the cartridge is in use, care must however be taken to allow the leader piece to be kept at the retracted position firmly in a proper posture or substantially in a proper posture within a permissible range in the event of an impact or shock imposed on the cartridge. However, as is well known to those skilled in the art, the single-reel tape cartridge for a specific application, for example, for use in a computer-based information processing environment is generally heavier than the two-reel tape cartridge and, therefore, the single-reel tape cartridge has a relatively large kinetic inertia.
Accordingly, in the event that the single-reel tape cartridge is inadvertently fallen down onto, for example, a floor, the single-reel tape cartridge is susceptible to a relatively high impact. For example, one or more reel locking pawls used to hold the tape reel in a stationary position within the cartridge housing when the tape cartridge is not in use may be instantaneously disengaged from the reel or damaged detrimentally, resulting in loosening of the length of magnetic recording tape that has been firmly wound around the reel hub. Loosening of the length of magnetic recording tape may be in turn accompanied by an undesirable displacement of the leader piece from the retracted position or separation of the leader piece out of the cartridge housing.
The retracted position for the leader piece is generally defined within the cartridge housing and at a location adjacent to and inwardly of the tape window defined in a part of the peripheral wall of the cartridge housing. The tape window is selectively opened or closed by a door member so that when the door member is in a closed position, the reel chamber can be protected from potential sources of harm such as dust and particulate contaminants that would give rise to damage to the magnetic tape within the reel chamber.
Accordingly, in the event that the tape cartridge is inadvertently fallen onto the floor with the leader piece consequently displacing from the retracted position and/or departing from the proper posture, no one can ascertain whether or not the leader piece has displaced or departed, unless one looks into the reel chamber externally through the window by opening the door. In most cases, however, unless the tape cartridge housing including the door is physically deformed and/or damaged in its appearance even though the leader piece inside the cartridge housing would have displaced from the retracted position and/or departed from the proper posture, such tape cartridge is provided for actual use in the tape drive. The outcome would be that the catch member, forming a part of the automatic tape threading mechanism built in the tape drive, fails to catch or grab the leader piece. This is indeed detrimental to obtainment of consistently smooth tape winding within the tape drive preparatory to data recording or retrieval.
Accordingly, the present invention is primarily intended to provide an improved, highly reliable single-reel tape cartridge including the leader piece that is held firmly at the retracted position in a proper posture regardless of whether or not the impact acts on the tape cartridge, to thereby ensure obtainment of consistently smooth tape winding within the tape drive preparatory to data recording or retrieval.
In order to accomplish this and other objects of the present invention, there is in accordance with the present invention provided a single-reel tape cartridge cooperable with an operatively compatible tape drive including a tape catch member, which cartridge includes a cartridge housing having a tape window defined therein, and a single reel rotatably accommodated within the cartridge housing and having a roll of a length of magnetic recording tape coaxially mounted thereon. The length of magnetic recording tape has one end anchored to the reel and the opposite end provided with a leader member that is positioned adjacent the tape window. The leader member is engageable with the tape catch member when the length of magnetic tape is to be drawn out of the cartridge housing and into the tape drive. A releasable locking mechanism is provided, including a pair of first locking members and a second locking member cooperable with each other to lock the leader member at a retracted position at which the leader member is housed within the cartridge housing and positioned adjacent the tape window. The first locking members are secured to top and bottom panels of the cartridge housing adjacent the tape window for receiving the leader member at the retracted position in a predetermined posture whereas the second locking member is positioned adjacent the tape window and cooperate with the first locking members to lock the leader member at the retracted position.
According to the present invention, because of the use of the releasable locking mechanism in the single-reel tape cartridge, even though the leader member undergoes a motion under the influence of impact imposed on the tape cartridge as a result of the tape cartridge being, for example, fallen onto a floor, the leader member can advantageously be retained and locked at the retracted position without substantially displacing in position. Accordingly, when the length of magnetic tape is desired to be drawn out of the tape cartridge, no misalignment of the catch member on the part of the tape drive with the leader member in the tape cartridge will occur substantially. Thus, the present invention is effective to ensure a sure engagement of the catch member with the leader member.
In a preferred embodiment of the present invention, the leader member is in the form of a leader pin having a hooking arm connected to each of opposite ends of the leader pin so as to extend generally perpendicular to the leader pin. The hooking arms on the respective ends of the leader pin can cooperate with the catch member to allow the latter to engage the leader member when the length of magnetic tape is to be drawn out of the cartridge housing.
In such case, the second locking member may include an elongated lock body supported by the cartridge housing, and a biasing spring housed within the cartridge housing for urging the elongated lock body in a direction required for the elongated lock body to engage the leader pin. The second locking member may be either pivotally supported or fixedly supported in the cartridge housing.
More specifically, the second locking member may include a bearing boss journalled by and within the cartridge housing for angular movement about its own longitudinal axis, an elongated lock body formed integrally with the bearing boss so as to extend in a first direction generally perpendicular to the longitudinal axis of the bearing boss, and a lock release piece formed integrally with the bearing boss so as to extend in a second direction counter to the first direction, said elongated lock body applying a retaining force to the leader pin to lock the leader pin at the retracted position in cooperation with the first locking members.
Alternatively, the second locking member may include a bearing boss disposed within the cartridge housing with its own longitudinal axis perpendicular to a lengthwise direction of the magnetic tape, an elongated lock body formed integrally with the bearing boss so as to extend in a first direction generally perpendicular to the bearing boss, said elongated lock body including at least one lock arm having a free end thereof bifurcated to define a pair of elastically deformable embracing pieces for receiving the leader pin 14 therein, and at least one receiving arm having a free end thereof formed with a hook for holding the leader pin, and wherein a direction of detachment of the leader pin relative to the lock arm and a direction of detachment of the leader pin relative to the receiving arm lie at an angle to each other.
Again alternatively, the second locking member may include a bearing boss disposed within the cartridge housing with its own longitudinal axis perpendicular to a lengthwise direction of the magnetic tape, an elongated lock body formed integrally with the bearing boss so as to extend in a first direction generally perpendicular to the bearing boss, said elongated lock body including a pair of receiving arms for engagement with opposite ends of the leader pin in a direction outwardly of the cartridge housing and a lock arm for receiving a portion of the leader pin intermediate between the opposite ends thereof.
The number of one or both of the receiving arms and the lock arms may not be limited to one, but two or more of them can be employed.
Preferably, the cartridge housing may have a pivotally supported door for selectively closing or opening the tape window and having an inner side face leading towards an interior of the cartridge housing, in which case the inner side face of the door is preferably configured to retain the leader pin at the retracted position when the door is in position to close the tape window.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.